1. Field of the Invention
The present invention relates to a memory card having an erroneous erase preventing function and its control apparatus, and a data transmission/reception apparatus.
2. Description of the Prior Art
Conventionally, an external storage apparatus such as a magnetic tape, magnetic disc, optical disc, memory card and the like is used for storing a data from an electronic apparatus such as computer, digital still camera and the like. Especially, the memory card is widely used for its convenience for carrying and high transfer rate.
Similarly as a flexible disc, a memory card as an erroneous erase prevention switch for preventing an erroneous erase of a data stored. However, a conventional erroneous erase prevention switch is provided on a main plane of the card memory body and a user cannot operate the switch when the memory card is mounted on an electronic apparatus.
In this case, if the memory card is inserted into an electronic apparatus and the user find that the memory card is disabled for writing, the user cannot write a new data on a data already stored. The user should pull out the memory card from the electronic apparatus., set the erroneous erase prevention switch to a writable mode, and again mount the memory card into the electronic apparatus. It has been desired to improve the switching operationability of the erroneous erase prevention switch.
It is therefore an object of the present invention to provide a memory card capable of preventing an erroneous erase of a data stored or another data writing on the data stored, while enabling to freely set the erroneous erase prevention switch to a desired mode, and its control apparatus, and its data transmission apparatus.
In order to achieve the aforementioned object, the memory card according to the present invention is a memory card for storing a data transmitted from a control apparatus, the memory card including: storage means for storing a data from the control apparatus: a switch for setting whether to inhibit writing of a data in the storage means; and control means for controlling writing of the data transmitted from the control. apparatus, on the storage means.
In the memory card, the switch can be switched even when the memory card is mounted on the control apparatus; and the control means decides a setting content of the switch when writing a data transmitted from the control apparatus and transmits a write enabled signal to the control apparatus unless the switch is set to a write disabled mode, and transmits a write disabled signal to the control apparatus if the switch is set to a write disabled mode.
The memory card control apparatus according to the present invention is a memory card control apparatus for controlling write and read of a data into/from a memory card, including: storage means for storing a data to be transmitted to the memory card; and control means for controlling write-in and read-out of a data into/from the storage means.
The control means functions in such a manner for each data write it is decided whether the memory card is set to a data write disabled mode; when a write enabled signal is received from the memory card, a data stored in the storage means is read out and written on the memory card; and when a write disabled signal is received from the memory card, read out of the data from the storage means is interrupted.
The data transmission and reception apparatus according to the present invention is for carrying out a data transmission and reception between a control block and a memory card, wherein the memory card includes: first storage means for storing a data from the control block; a switch for setting to inhibit writing of a data to the first storage means; and first control means for controlling write-in and read-out of a data into/from the first storage means, whereas the control block includes second storage means for storing a data to be transmitted to the memory card and second control means for controlling a data write-in and read-out into/from the second storage means.
In the data transmission and reception apparatus, the memory card, when writing a data transmitted from the control block, decides the setting content of the switch. Unless the switch is set to a write disabled mode, a write enabled signal is transmitted to the control block, and if the switch is set to a write disabled mode, a write inhibit signal is transmitted to the control block, thus controlling writing of a data transmitted from the control block, in the first storage means. Moreover, the first control means, for each data, decides whether the memory card is set to the data write inhibit mode. When the control block receives a write enabled signal from the memory card, the data stored in the second storage means is read out and is written in the first storage means. When a write inhibit signal is received from the memory card, read out of the data from the second storage means is interrupted.